Electric cigar lighter with thermostatic bimetallic current control

ABSTRACT

An instant cigar lighter comprising a holder adapted for mounting on an automobile dashboard, an elongate igniter plug receivable in the holder and having a spiral heating coil disposed at its inner end, a metal cup surrounding the heating coil and at one end connected thereto, and means for establishing an electrical circuit through the cup and heater coil to enable energization of the latter. The lighter is intended for use with a source of power having a higher voltage than the voltage rating of the coil, and has special heat responsive means comprising a bimetal disk engageable with the rim of the cup and closely juxtaposed to the heating coil for substantially instantly opening the circuit in response to heating of the coil to a useful predetermined temperature. The bimetal disk and the metal cup can cooperate to constitute a tightly closed enclosure closely surrounding the heating coil, the disk comprising one large wall of the enclosure whereby heat from the coil is immediately experienced by the disk to effect a very rapid response of the latter. The voltage rating of the heating coil can be one-half of the output voltage from the power source such that the coil becomes heated at a greatly increased rate and reaches a useful temperature in a period of less than several seconds, after which its circuit is opened to prevent burn-out.

United States Patent [1 1 Fenn et al.

[451 Sept. 18,1973

1 ELECTRIC CIGAR LIGHTER WITH THERMOSTATIC BIMETALLIC CURRENT CONTROL[76] Inventors: Lawrence E. Fenn, 40 Anchorage [22] Filed: June 9, 1972211 Appl. No.1 261,233

[52] 11.8. CI. 219/265, 219/267 [51] Int. Cl. F23g 7/02 [58] Field ofSearch 219/264, 265, 267

[56] References Cited UNITED STATES PATENTS 2,137,195 1lll938 Cohen219/264 2,151,622 3/1939 Sinko.... 219/264 2,207,462 7/1940 Kurtz....219/265 X 2,207,601 7/ 1940 Shakespeare et al 219/265 2,220,978 11/1940Shakespeare et a1... 219/265 2,503,103 4/1950 Eskuchen 219/264 2,637,7995/1953 Wood 219/265 3,381,109 4/1968 Youhouse 219/265 PrimaryExaminer-Volodymyr Y. Mayewsky Attorney-H. Gibner Lehmannet al. I

'l'l'l'l'l [57] .ABSTRACT An instant cigar lighter comprising a holderadapted for mounting on an automobile dashboard, an elongate igniterplug receivable in the holder and having a spiral heating coil disposedat its inner end, a metal cup surrounding the heating coil and at oneend connected thereto, and means for establishing an electrical circuitthrough the cup and heater coil to enable energization of the latter.The lighter is intended for use with a source of power having a highervoltage than the voltage rating of the coil, and has special heatresponsive means comprising a bimetal disk engageable with the rim ofthe cup and closely juxtaposed to the heating coil for substantiallyinstantly opening the circuit in response to heating of the coil to auseful predetermined temperature. The bimetal disk and the metal cup cancooperate to constitute a tightly closed enclosure closely surroundingthe heating coil, the disk comprising one large wall of the enclosurewhereby heat from the coil is immediately experienced by the disk toeffect a very rapid response of the latter. The voltage rating of theheating coil can be one-half of the output voltage from the power sourcesuch that the coil becomes heated at a greatly increased rate andreaches a useful temperature in a period of less than several seconds,after which its circuit is opened to prevent burn-out.

9 Claims, 7 Drawing Figures 52 F198 53 64 63 2832 50 20 enPATENTEDSEPHBIBB I l 3 760 150 SHEET 1 U? 2 ELECTRIC CIGAR LIGHTER WITHTHERMOSTATIC BIMETALLIC CURRENT CONTROL BACKGROUND This inventionrelates generally to cigar lighter devices, and more particularly tolighters of the type employing an electrically energized heating coildisposed in a manually operable igniter plug which is receivable in apanel-mounted socket. In the past, large numbers of different lighterconstructions of the above type have been proposed and developed. Ingeneral, most employed a spiral heating coil disposed within acylindrical cup, the annular surface of the cup being engageable bybimetal fingers carried in a socket of a holder structure. In thedevices heretofore proposed the continuous voltage ratingof the coil hadto be substantially equal to the output voltage of the source appliedthereto, to prevent severe overheating and subsequent burn-out of theheating element before the relatively slow-heating bimetal fingersoperated to release the plug and open the circuit. As aresult, invirtually all cases the element would require ten or more seconds toreach the incandescent temperature which would satisfactorily provide alight for a cigar or cigarette.

:Roughlyover 40 years have passed since the beginning of cigar lightertechnology, and the problem of shorten ing the interval betweenactuation of the lighter and heating of the elementto adequateincandescence has existed and'hasdefeated attempts to solve it nearly aslong. In this period of more than 40 years there has been achievedvirtually no substantial progress toward economically solvingtheproblem. Inaddition, quite a few of the lighter designs of the pasthave 'had a large number of individual parts, thus requiring adherenceto closetolerances. Also, many were relatively expensive to manufactureand maintain while giving no worth- :while advantages. Frequently, inlighters employing spring fingers to momentarily retain the igniter plugin the energized position, problems occurred with breakage or bending ofthe fingers after a number of operations. Such broken fingers wouldfrequently cause a short circuit in the socket, which led to abnormallyhigh currents flowing in the leads running between the battery andsocket. This inevitably resulted in either a blown fuse or else a firein the electrical cabling, the latter sometimes having disastrous anddamaging effects.

SUMMARY cially simple and economical in construction and reliable inoperation, but which successfully provides the long-eluded very rapidheating response following its initial actuation. A related object isthe provision of an instant" lighter as above characterized, wherein thecost ofmanufacture is substantially less than that of lighter devicescurrently produced.

The above objects are accomplished by the provision of a combinationcomprising a holder device presenting a socket, an igniter plugreceivable in said socket, an electrical circuit comprising a heatingelement carried by the igniter plug and characterized by a certaincontinuous duty voltage rating, a source of power providing a voltage tosaid circuit substantially greater than said continuous voltage ratingof the coil and a unique heat-responsive means which is closelyjuxtaposed to the heating element and which completely opens the circuitthereof substantially instantly in response to heating of the element toa predetermined useful temperature. The heating element is disposed inand electrically connected to a metal cup having a sharp rim portionconstituting an electrical contact, said cup being mounted on the innerend of the igniter plug. The said heat responsive means comprises abimetal disk especially arranged to be engageable with the sharp rim ofthe cup and to effect electrical contact thereto. Upon actuation of thelighter plug, the contact established between the disk and sharp edge ofthe cup effects quick heating of the coil, which then immediately causesthe edge portions of the bimetal disk (which are in contact with the cuprim) to snap backward so as to disengage the cup, thus completelyopening the circuit and de-energizing the heating element just when itsuseful predetermined temperature has been reached. The disk and cuptogether can form a flat, almost wafer-like enclosure which closelyconfines the heating element. The bimetal disk constitutes one largeside wall of this enclosure, disposed broadside to the element. Withsuch an arrangement a very rapid and reliable response of the disk tothe heat is had, and also there results a reliable, instant opening ofthe circuit when the element attains the proper operating temperature.Since the continuous voltage rating of the element is only a fraction ofthe applied voltage, the heating of the coil occurs at a greatlyincreased rate, thus providing a substantially instant lighter which ischaracterized by aresponse on the order of two seconds or so. Thebimetallic snap disk is especially simple and foolproof as compared withthe previous construction involving a plurality of stamped, bimetalfingers whereby the cost is appreciably reduced and the reliability isincreased.

Other objects and advantages will hereinafter appear.

in the figures, illustrating several forms of the invention:

FIG. 1 is an axial sectional view of the improved lighter of the presentinvention, showing the igniter plug in the shallow, unenergized positionprior to actuation.

FIG. 2 is a similar view of the lighter, showing the igniter plug fullydepressed to its deep, energizing position wherein the cold bimetal diskengages the sharp rim of the metal igniter cup.

FIG. 3 is an axial sectional view of the lighter, showing the igniterplug fully depressed to its deep, energizing position and showing thebimetal disk sprung or snapped to its circuit opening position whereinit is out of engagement with the metal cup on the igniter plug.

FIG. 4 is an axial sectional view of the lighter, showing the igniterplug replaced to its shallow position in the holder after use; thebimetal disk is shown as being still sufficiently hot to remain in thecircuit opening position of FIG. 3.

FIG. 5 is an axial sectional view of another embodiment of theinvention, wherein two spring-like latching clips are employed to retainthe bimetal disk in its snapped position, disengaged from the igniterplug until the latter is either removed or else replaced, depending onthe timing and the heat loss from the disk.

FIG. 6 is an inside elevational view of a thermostatic control member inthe form of a disk with slabbed-off sides, which is substitutable forthe full disk control of FIGS. 1-5.

FIG. 7 is a fragmentary side elevational view of a modified holderdevice employing a back-up spring ring to reinforce lanced springfingers.

Referring first to FIG. 1, there is illustrated a cigar lightergenerally designated by the numeral 10, comprising a holding device 12having an annular flange 14 adapted to engage a supporting panel 16 suchas the dashboard of an automobile. The holding device has a threaded endportion 18 which receives a cylindrical mounting member 20, the latterbeing adapted to en gage the rear face of the supporting panel 16 tothereby support the holding device 12 in a well known manner. Theholding device 12 presents an outwardly facing socket 21 in which thereis receivable an elongate igniter plug 22having an outer electricallyconducting shell 23 the inner end portion of which constitutes an ashguard. The plug 22 further includes a spiral heating coil or element 24located at that end which is received in the socket 21, and a metal cup26 having a sharpedged rim portion 28 which surrounds the coil as wellas a stud 30 that is fastened to the inner end of the coil to therebyprovide support for and carry current from the latter. The outer end ofthe coil 24 is preferably welded to the metal cup at location 32.

As illustrated in FIG. 1 the metal cup 26 is carried by the stud 30 butis electrically insulated therefrom by means of a pair of insulatedwashers 34 and 36 which can be of mica or other heat-resistantinsulating material. The washers 34 and 36 are tightly secured to theopposite faces of the disk-shaped bottom wall of the cup by a retainerwasher 38 and bushing 40. The stud 30 is secured to the body 41 of theigniter plug by means of a support bushing 42 disposed within theconducting shell 23; the stud thus being electrically connected to theshell to carry current thereto.

By the above arrangement an electrical circuit through the igniter plugis established, beginning at the contact rim 28 of the metal cup 26,through the heating coil 24 to the stud 30 and thence to the outerconducting shell 23. The igniter plug further comprises a knob 44 on thebody 41, by which the unit can be readily grasped and held. The stud 30is threaded for a portion of its length and is inserted in a tapped hole46in the body 41. An additional bushing 48 provides a convenient meansfor securing the plug body 41 to the conducting shell 23.

In FIG. 1 there is further illustrated one of a plurality of lancedspring fingers 50 integral with the annular wall of the holding device12. The igniter plug is provided with an annular groove 52 about itsperiphery for cooperation with the lanced fingers 50. The spring fingers50 bias the igniter plug to the shallow position illustrated in FIG. 1,hereinafter also referred to as the storage or unenergized position. Theigniter plug can be depressed from such position to the energizingposition illustrated in F IG. 2 against the action of the spring fingers50, this position hereinafter being also referred to as the deep"position.

In accordance with the present invention there is provided a novel andunique automatic circuit control by which a surprisingly new andstriking result is obtained,

that of being able to substantially instantaneously heat the coil touseful incandescence without causing any overheating or bum-out thereof.This improved circuit control establishes an electrical circuit from oneportion of the holding device through the metal cup and heating coil toanother portion of the holding device and is characterized by anespecially simple and effective heat-responsive member closelyjuxtaposed to the heating coil and adapted to substantially instantlycompletely open the electrical circuit thereof in response to extremelyquick heating of the coil to a pre-determined useful temperature. Inconjunction with said automatic control there is utilized a source ofpower which provides a voltage substantially greater than thecontinuous-duty voltage rating of the coil, as for example a voltage oftwice said rated voltage. Thusthe coil 24 could be a 6-volt coil, andthe power source could be a l2-volt battery.

FIG. 1 illustrated the novel control as comprising a thermostatic,dish-like member of large expanse, in the form of a bimetal disk 54mounted in the socket 21 of the holding device 12 and supported by athreaded stud 56, the latter being secured to the holding device bymeans of a threaded bushing 58, washer 60 and nut 62. The bimetal disk54 has an annular peripheral contact portion 64 adapted to engage thesharp edge 63 of the rim 28 of the metal cup 26, the contact portion 64thus constituting one part of a means for establishing an electricalcircuit from one portion of the holding device through the igniter plugand to another portion of the holder. As illustrated in FIG. 1, thepower source can comprise a 12-volt battery 66 having one terminal 67permanently connected to the stud 56 and the other terminal 68 connectedto the panel 16 of the dashboard (not necessarily at the locationshown). It will be understood that when the igniter plug occupies theshallow position of FIG. 1 the conducting shell 23 will be at the samepotential as the battery terminal 68, since the panel or ground 16contacts the annular wall of the holding device 12 which in turncontacts the shell 23.

The invention provides that the heating coil 24 be characterized by aparticular continuous duty voltage rating, representing the maximumvoltage which can safely be applied thereto for a prolonged period oftime without causing damage due to overheating, and that the battery 66supply a voltage substantially in excess of such continuous voltagerating, whereby the continuous-duty rating is a fraction of theavailable output voltage range supplied by the battery. As previouslymentioned, the coil could be one rated for six volts whereas the battery66 could have a potential of 12 volts. If recharged by an alternator, asin the case of an automobile, the battery voltage could be brought up toa somewhat higher value. By this arrangement, the coil heats in abouttwo seconds or substantially instantly, and thus would be subject toburn-out if energized by this source for an interval of more thanseveral seconds.

The operation of the present cigar lightercan now be readily understoodby referring to FIGS. 1-4. The igniter plug 22 is normally yieldablyheld in the shallow position of FIG. 1 by the spring fingers 50, and thebimetal disk 54 when at ambient temperature has the position shown.Actuation of the lighter is effected by manually depressing the knob 44such that the plug 22 is shifted further into the socket, to the deepposition illustrated in FIG. 2. As this is done, the sharp-edge 63 ofthe rim 28 of the cup 26 engages the contact portion or surface 64 ofthe bimetal disk 54 and applies a force to the latter such as to causeit to become slightly less concave. As a consequence, the contact areaand pressures existing between the cup 26 and disk 54 are maximizedwhereby more reliable electrical connection is established therebetween.The edge 63 of the rim 28 presses uniformly against the disk, resultingin a effective contact pressure. After the rim 28 has thus slightlyflattened the disk, the ash guard 23 of the plug engages the bushing 58whereby the latter provides a fixed abutment vfor positively determiningthe insertion limit of the plug into the deep position. Accordingly, thedanger of depressing the plug too far and thus possibly permanentlydeforming or damaging the disk 54 is effectively eliminated.

At the time that the disk 54 is engaged by the cup, the coil 24virtually instantaneously heats to incandescence. The phraseinstantaneous as used herein is intended to denote a time intervalgenerally on the order of two seconds, one and one-half seconds or less.The proximity of the coil to the disk and the tight, closely fittingenclosure formed by the cup and disk with the disk forming one largewall broadside to the coil, all cause the disk to become heated veryquickly, and as a result its periphery snaps backward or to the left asviewed in the figures, whereby the annular contact portion or area 64moves axially away from the coil 24 and edge 63 of the cup 26, to thuscompletely open the circuitand de-energize the coil. The plug must beheld in during this very short interval, at least a second or so, oruntil an audible snap of the disk is heard, at which time the igniterplug is sufficiently heated and ready for use.

FIG. 3 illustrates the plug in the deep position immediately after thedisk has snapped away from the cup and with the plug still being heldin. If the lighter plug is now released, it will assume the positionillustrated in FIG. 4, which is identical to that of FIG. 1 except thatthe disk is still hot and occupies the opposite convex position shown.It will be understood, of course, that after the snap of the disk isheard, the plug can be immediately removed for use, and the coil 24 willbe in an incandescent state. However, the proper operation of thelighter does not depend on hearing the disk snap. The user merely judgesthe short two-second or less time interval and quickly learns the rapidtiming that is possible by virtue of the fast, unique automatic circuitcontrol provided by the invention.

We have found that a coil having a six-volt rating operates verysatisfactorily in the above described manner when energized from anominal 12-14 volt source, generally providing a useable coilincandescence in less than 1.5 seconds. The greatly increased heating isrealized because the power supplied to the 6-volt coil 24 as energizedfrom l2 volts is four times that which would be supplied by a 6-voltsource. In consequence, instead of requiring 6 or more seconds as is thecase where a 6-volt'source is employed the coil as automaticallycontrolled in the lighter of the present invention reaches incandescencein 1.5 seconds, which is a truly great advance and improvement inlighter technology. The coil 24 does not suffer from damage due tooverheating, since the actual temperature attained is no more than wouldnormally occur in a conventional 6- volt unit energized from a 6-voltbattery. However, by thepresent invention, the coil 24 reaches such atemperature much sooner. The proximity of the bimetal disk 54 to thecoil 24 insures that rapid heating of the disk will occur, and that thecircuit will be opened before excessive coil temperatures are realized.

Another embodiment of the invention is illustrated in FIG. 5. A holdingdevice is shown, presenting an outwardly facing socket 71 in which thereis receivable an elongate igniter plug 72. The plug 72 comprises a metalcup 74 having a sharp edge 75 on the rim portion 76, and having aheating coil 77 disposed therein similar to the coil 24 discussedinconnection FIGS. 1-4. The cup 74 is carried by a threaded stud 78 and iselectrically insulated therefrom by insulating washers similar to thosedesignated 34 and 36 in FIG. 1, one of which is shown in FIG. 5 anddesignated 80. The stud 78 is threaded into a threaded spacer and clampbushing 82, and into a tapped hole 84 in the body 85 of the knob 86 ofthe plug. A metal cup 88 of the knob surrounds but is spaced from theconducting cup 74 of the plug 72. The holding device has a plurality oflanced spring fingers 89 which cooperate with a contact or conductivesleeve 91 press-fitted onto the cup 88 to normally bias the igniter plugto the shallow position illustrated in FIG. 5. With the abovearrangement the metal shell 70 of the holding device is at groundpotential, being grounded to the panel 94, and thus the ground potentialappears on the cup 88 and stud 78 of the igniter plug. A cylindricalmounting or clamping member 92 is employed to retain the holding deviceon the panel 94 (which could be the automobile dashboard or instrumentpanel)." I

As with the previous embodiment of the invention there is provided abimetal circuit-control disk 96 disposed in the socket of the holdingdevice 1 70 and mounted on an electrically insulated stud 98. The stud98 is secured in place by an insulated threaded bushing 100, and by awasher 102 and nut 104. In this embodiment of the invention a disklatching means is provided, comprising a pair of spring fingers 106, 108which can temporarily latch the disk 96 in its heated, circuitopeningposition (shown in dotted lines in FIG. 5). The latching fingers 106,108 are carried by the insulated bushing 100, and have camrning controlportions 110, 112 which are engageable with an external annular beaddisposed on the igniter plug. The fingers 106 and 108 can beadvantageously constituted of phosphor-bronze to provide adequateresilience. As shown, the fingers 106 and 108 carry insulating wedges107 and 109 respectively, which can have elongate ribs 111, 113press-fitted into slots of the fingers. The wedges are preferablyconstituted of an electrical insulating material such as aluminum oxide,in order to electrically insulate the bimetal disk from the springfingers when the latter are engaging the disk. This preventsshort-circuiting between the disk 96 and the holding device 70..

The operation of this embodiment of the invention can now be readilyunderstood. As in the previous embodiment, a battery 118 having anominal l2-volt output is employed to energize the heating coil whichlatter has a continuous voltage rating equal to a fraction of the outputvoltage of the battery 118, as for example one-half. When the igniterplug is held depressed so that the annular stop shoulder 114 of the plugengages the holding device mounting flange 1 16, the sharp edge 75 ofthe rim 76 of the cup 74 engages the bimetal disk 96 in a manneridentical to that discussed in connection with FIGS. 1-4. Thisengagement of the cup 74 and disk 96 closes the circuit through thecoil, and as a result the latter is quickly heated to incandescence. Dueto the proximity of the disk and coil to each other, some of the heatfrom the latter is transferred to the disk virtually immediately, thuscausing the edge portion of the bimetal disk to snap back or axiallyaway from the cup to the position indicated in dotted lines in FIG. 5.The particular configuration of the insulating wedges 107 and 109enables the disk to momentarily cam the fingers 106 and 108 outwardlyand thus snap past the sharp-angled shoulders of the wedges 107, 109.The disk 96 will now remain latched in the hot position shown in dottedlines, and this will continue even after the disk cools, until it isreleased by outward flexing of the fingers 106 and 108. As seen in FIG.the fingers 106, 108 have rounded control portions 110, 112respectively,"which cooperate with the annular bead 120 of the igniterplug.

it will now be noted that if the igniter plug 72 is inadvertently heldin the deep position for a period of time longer than that required toheat the coil, the bimetal disk will become latched away and will remainso, since the control portions 110 and 112 are normally positionedinwardly. By this arrangement there is eliminated any danger ofoverheating of the coil due to cycling of the bimetal disk, should theplug be inadvertently held in the deep position.

' At the time that the plus 72 is released or removed, the bead 120 willurge the spring fingers 106, 108 outwardly a sufficient amount torelease or unlatch the bimetal disk. Assuming the disk has cooledsufficiently, it will now assume its normal positionillustrated in solidlines in FIG. 5. By the above arrangement, once the coil has been heatedand the disk has snapped away from the cup, it will remain latched inthe circuit opening position until the igniter plug is either releasedor removed. There is thus no danger of overheating of the coil due tocycling of the bimetal disk.

As at present understood, the unexpected and surprisingly excellentsuccess of the cigar lighter of this invention in safely providinginstantaneous lights resides in the unique structure and mode of theoperation above described wherein the thermostatic dish-like member ordisk is one of two large walls of a small enclosure which closelyconfines the heating element, to the end that the member ordisk receiveslarge amounts of heat quickly to effect reliable breaking of the circuitas the heating element attains its useful incandescence.

Still another embodiment of the invention is illustrated in FIG. 6,wherein a thermostatic snap member 54a of dish-like configuration iscarried by a stud 56a, these parts being substitutable for the disk 54and stud 56 of FIGS. 1-5. The member 54a can be formed of a snap diskhaving'two opposite'side portions slabbed off to provide straight edgesas shown, or else it can be formed from bimetallic strip stock havingthe desired width. Operation of the member 54a is similar to that of thedisk 54; essentially it completely closes the mouth of the cooperableheating element cup 26, as will be understood, so as to confine theelement and receive a large amount of heat therefrom.

Yet another embodiment of the invention is shown in FIG. 7, whichdepicts a holder device 70a comprising a shell having outwardly lancedpairs of tabs 120 which position a split spring ring 122 that reinforcesspring fingers 89a also lanced from the shell. The holder accommodatesthe igniter plug 72a having a metal cup 88a and conductive sleeve 91a,functioning like the similarly-numbered parts already explained above.By the provision of the spring 122 assurance is had that the fingers 890will reliably bias the plug 72a to the opencircuit, storage positionwhen finger pressure is removed. During outward deflection of thefingers 89a the spring 122 will yield slightly, as can be understood.

From the above it can be seen that we have provided a novel and improvedinstant lighter which is especially simple and inexpensive to produce,reliable in operation and which yields the surprising and unobviousresult of safe, instant heating. The construction shown has been, byactual test, found to represent a very workable and practical solutionto a problem which has existed for several decades, and thus it is seento represent a distinct advance and improvement in cigar lightertechnology.

Variations and modifications are possible without departing from thespirit of the invention.

We claim:

1. A cigar lighter apparatus, comprising in combination:

a. a holding device having means for attaching it to a supporting panel,said device presenting an outwardly-facing socket,

b. an elongate igniter plug adapted to be received in the socket of theholding device, said plug being movable therein between shallow and deeppositions and having a spiral heating coil at its inner end,

c. a metal cup surrounding and connected to the heating coil,

d. means establishing an electrical circuit from one portion of theholding device through the metal cup and heating coil of the igniterplug and back to another portion of the holding device in response tomovement of the igniter plug from its shallow position in the socket toits deep position therein, thereby to effect energization of the coil,

e. said circuit-establishing means comprising a sharp edge on the rim ofthe metal cup and comprising an annular cooperable electrical contact onthe holding device,

f. a source of electrical power having a given nominal output voltagerange, connected to said portions of the holding device, and

g. a substantially flat heat-responsive means juxtaposed and disposedbroadside to said heating coil for substantially instantly actuatingsaid circuitestablishing means to completely open said electricalcircuit in response to rapid heating of the coil to a predetermineduseful temperature,

b. said heat-responsive means comprising a bimetallic, thermostaticdish-like member of large expanse which responds to heat by moving saidannular contact axially away from said heating coil and rim of the metalcup of the igniter plug when the latter is continuously held in its deepposition in the holding device, said member when cold having a concaveside facing the heating coil,

i. the continuousduty voltage rating of said heating coil being afraction of the nominal output voltage of said electrical power sourcesuch that the coil would heat substantially instantly and quickly burnout if the circuit through it remained closed for more than severalseconds.

2. The invention as defined in claim 1, wherein:

a. said plug has an annular exterior groove,

b. said holding device having a lanced spring finger receivable in saidgroove for normally biasing the plug to its shallow position in thesocket.

3. The invention as defined in claim 1, and further including:

a. latching means releasable upon removal of the igniter plug from theholding device, for latching the dish-like member in its heated, circuitopening position.

4. The invention as defined in claim 3, wherein:

a. said latching means comprises a pair of spring fingers carried by theholding device and disposed at peripheral portions of the dish-likemember,

b. said spring fingers having control portions which are engageable withthe igniter plug to spread the fingers apart when the plug is in itsshallow position.

5. The invention as defined in claim 1, wherein:

a. the annular contact of the holding device comprises a peripheralportion of the dish-like member,

b. said cup and dish-like member when engaged constituting asubstantially fiat, circular wafer-like enclosure closely confining theheating coil with the dish-like member comprising one large wall of theenclosure, disposed broadside and closely juxtaposed to the coil,

c. said dish-like member at its peripheral portion snapping away fromthe sharp edge on the rim of the metal cup when the heating coil reachesa useful incandescence.

6. The invention as defined in claim 5, wherein:

a. the dish-like member is engaged by the sharp edge of the cup andslightly flattened by force exerted by said edge as the plug reaches itsdeep position in the holding device, thereby establishing a moreeffective electrical contact between the dish-like member and sharp edgeof the cup rim due to the increased force existing therebetween.

7. The invention as defined in claim 2, and further including:

a. a back-up spring carried by the holding device and bearing againstsaid lanced spring finger to reinforce the biasing action of the same.

8. The invention as defined in claim 7, in which:

a. the back-up spring comprises a ring encircling the holding device andengaging an outer surface of the spring finger.

9. The invention as defined in claim 1, in which:

a. thedish-like member comprises a disk adapted to completely close-overthe mouth of the cup.

* I II

1. A cigar lighter apparatus, comprising in combination: a. a holdingdevice having mEans for attaching it to a supporting panel, said devicepresenting an outwardly-facing socket, b. an elongate igniter plugadapted to be received in the socket of the holding device, said plugbeing movable therein between shallow and deep positions and having aspiral heating coil at its inner end, c. a metal cup surrounding andconnected to the heating coil, d. means establishing an electricalcircuit from one portion of the holding device through the metal cup andheating coil of the igniter plug and back to another portion of theholding device in response to movement of the igniter plug from itsshallow position in the socket to its deep position therein, thereby toeffect energization of the coil, e. said circuit-establishing meanscomprising a sharp edge on the rim of the metal cup and comprising anannular cooperable electrical contact on the holding device, f. a sourceof electrical power having a given nominal output voltage range,connected to said portions of the holding device, and g. a substantiallyflat heat-responsive means juxtaposed and disposed broadside to saidheating coil for substantially instantly actuating saidcircuit-establishing means to completely open said electrical circuit inresponse to rapid heating of the coil to a predetermined usefultemperature, h. said heat-responsive means comprising a bimetallic,thermostatic dish-like member of large expanse which responds to heat bymoving said annular contact axially away from said heating coil and rimof the metal cup of the igniter plug when the latter is continuouslyheld in its deep position in the holding device, said member when coldhaving a concave side facing the heating coil, i. the continuous-dutyvoltage rating of said heating coil being a fraction of the nominaloutput voltage of said electrical power source such that the coil wouldheat substantially instantly and quickly burn out if the circuit throughit remained closed for more than several seconds.
 2. The invention asdefined in claim 1, wherein: a. said plug has an annular exteriorgroove, b. said holding device having a lanced spring finger receivablein said groove for normally biasing the plug to its shallow position inthe socket.
 3. The invention as defined in claim 1, and furtherincluding: a. latching means releasable upon removal of the igniter plugfrom the holding device, for latching the dish-like member in itsheated, circuit opening position.
 4. The invention as defined in claim3, wherein: a. said latching means comprises a pair of spring fingerscarried by the holding device and disposed at peripheral portions of thedish-like member, b. said spring fingers having control portions whichare engageable with the igniter plug to spread the fingers apart whenthe plug is in its shallow position.
 5. The invention as defined inclaim 1, wherein: a. the annular contact of the holding device comprisesa peripheral portion of the dish-like member, b. said cup and dish-likemember when engaged constituting a substantially flat, circularwafer-like enclosure closely confining the heating coil with thedish-like member comprising one large wall of the enclosure, disposedbroadside and closely juxtaposed to the coil, c. said dish-like memberat its peripheral portion snapping away from the sharp edge on the rimof the metal cup when the heating coil reaches a useful incandescence.6. The invention as defined in claim 5, wherein: a. the dish-like memberis engaged by the sharp edge of the cup and slightly flattened by forceexerted by said edge as the plug reaches its deep position in theholding device, thereby establishing a more effective electrical contactbetween the dish-like member and sharp edge of the cup rim due to theincreased force existing therebetween.
 7. The invention as defined inclaim 2, and further including: a. a back-up spring carried by theholding device and bearing against said lanced spring finger toreInforce the biasing action of the same.
 8. The invention as defined inclaim 7, in which: a. the back-up spring comprises a ring encircling theholding device and engaging an outer surface of the spring finger. 9.The invention as defined in claim 1, in which: a. the dish-like membercomprises a disk adapted to completely close-over the mouth of the cup.